Comparison of Cyclic Fatigue Resistance of Flexer One, Waveone Gold and One Shape Rotary Nickel-Titanium (NiTi) Files in Artificial Canals - An In vitro Study

Background: Nickel–Titanium (NiTi) rotary instruments are widely used in endodontics due to their flexibility and efficiency. However, they are prone to cyclic fatigue, which can compromise clinical outcomes. Objective: The present investigation evaluates and compares the ability of Flexer One, WaveOne Gold, and One Shape NiTi rotary file systems to withstand cyclic fatigue in simulated root canal environments. Methods: Ninety newly-manufactured NiTi rotary files ( n = 90), divided equally among three brands ( n = 30), were subjected to artificial canal testing with a standardized curve. To determine the number of operational cycles before failure, the files were run until instrument separation occurred. To verify that cyclic fatigue was the only reason for failure, the length of the fragmented portion was measured. Results: Data analysis employed analysis of variance and further statistical comparison, revealing that Flexer One demonstrated notably superior resistance to fatigue, followed by WaveOne Gold and then One Shape ( P < .005). Conclusions: These findings suggest the Flexer One system is the most robust in resisting cyclic fatigue compared to its counterparts.